الفهرس | Only 14 pages are availabe for public view |
Abstract Microgrids have been considered one of the suitable and efficient alternatives for the integration of distributed generation units in the utility grid. Different types of microgrids have been presented in the literature such as AC microgrid and Dc microgrid. However, the conventional distribution network has given an advantage to AC microgrid over DC microgrid due to the ease of integration. Meanwhile, the appearance of dc loads such as plug-in electric vehicles, which needs charging stations, as well as the dc nature of renewable energy resources have shifted the sight to the dc microgrid which requires interfacing converters to be integrated to the distribution network so the cost increases drastically. Therefore, the hybrid AC/DC microgrids have been developed to overcome the drawbacks of either AC or DC microgrid. In order to profit of the remarkable aspects of AC as well as DC, an inter-linking converter (ILC) is required to transfer the power between the two sides of the microgrids, meanwhile maintain the ac sub-grid frequency as well as the dc sub-grid voltage within acceptable ranges. This thesis presents an autonomous strategy to control the power flow between the two sub-grids. In the first, an autonomous control for the ILC which has been developed based on the modified AC-DC droop control, has been used to eliminate the need for any communication layer between the distributed generators and the converter. A hysteresis window has been used in the proposed control strategy to eliminate one of the drawbacks of controlling the interlinking converter which is the continuous operation. Moreover, an adaptive filtering based on continuous mixed P-norm algorithm (CMPN) has been implemented within the control strategy of the ILC in order to eliminate the need of proper tuning of PI controller gains and to profit of its robustness against impulsive noise as the accuracy of implemented droop is mainly dependent on the measured data. Furthermore, the proposed control strategy has been investigated against different types of loads to ensure the validity of the control plan. A comparison has been held between the performance of the proposed strategy under the operation of PI control and the proposed CMPN. Moreover, all the proposed techniques have been tested and simulated using PSCAD/EMTDC software environment to ensure the validity of the suggested control strategy. |